1. Field of the Invention
The present invention relates to a method of and apparatus for filling powder into a cavity formed in a die.
2. Description of Related Art
In a conventional powder filling method, as disclosed in Japanese Utility Model Publication SHO 57-79119, powder in a powder box is dropped into a cavity formed in a die when the powder box is brought to a position just above the cavity.
However, in the conventional powder filling method, when air in the cavity is replaced by the dropped powder, light particles whirl up while heavy particles drop quickly so that unevenness in particle size distribution occurs in the cavity. As a result, it is difficult for a sinter made from the powder to have a uniform density distribution and an accurate dimension. To obtain a uniform distribution, it would be effective to shake the cavity, but shaking would make the filling time period too long.